Specification
Longitudinal adjuster for a vehicle seat
The invention relates to a longitudinal adjuster for a vehicle seat having the features of the preamble of claim 1.
A longitudinal adjuster of this type is disclosed in DE 100 50 959 B4, in which the first seat track has two opposing rows of detents and three detent plates are mounted in the second seat track. Each detent plate has on both longitudinal sides of the base body three teeth which protrude through slots of the second seat track and which may engage in the detents. In the normal case, locking without clearance is implemented by means of at least one of the detent plates. In the event of a crash, webs between the slots are deformed so that at least one further detent plate is effective above a specific load.
The object of the invention is to improve a longitudinal adjuster of the aforementioned type, in particular to reduce constructional space and weight. This object is achieved according to the invention by a longitudinal adjuster having the features of claim 1. Advantageous embodiments form the subject-matter of the sub-claims.
detent plates with only two teeth per row of detents (i.e. generally for each longitudinal side of the detent plates) make it possible to reduce the necessary overlapping region of the seat tracks (relative to longitudinal adjusters with detent plates with three teeth per longitudinal side) whereby the range of the adjustable longitudinal positions of the seat is increased (with the same length of the seat tracks). As different detent plates are responsible for the locking, it may be ensured that locking is possible without clearance in all longitudinal positions of the seat. This freedom from clearance is implemented by
teeth of different detent plates, for which the distribution of the teeth and the detents is preferably selected to be variable.
A variable distribution of detents and teeth of the detent plates permits a specific design of the second seat track, which preferably comprises slots from which the teeth of the detent plates protrude, and recesses which specifically weaken the material between the slots. The distribution may be selected so that the webs between the slots and recesses all have the same width. Under load, therefore, all the webs are uniformly plasticized, so that in all situations a support of further teeth is possible.
The invention is described in more detail hereinafter with reference to an exemplary embodiment shown in the drawings, in which:
Fig. 1 shows a vertical section through the exemplary embodiment in the x-z plane along the line I-I in Fig. 2,
Fig. 2 shows a vertical section through the exemplary embodiment in the y-z plane,
Fig. 3 shows a horizontal section through the exemplary embodiment along the line III-III in Fig. 2,
Fig. 4 shows a schematic view of a vehicle seat, and
Fig. 5 shows a partially sectioned, partial perspective view of the exemplary embodiment.
A vehicle seat 1 of a motor vehicle has a longitudinal adjuster 3, by means of which the vehicle seat 1 may be longitudinally adjusted, i.e. the longitudinal seat position thereof being able to be adjusted in the
longitudinal direction of the seat x. The longitudinal direction of the seat x generally extends parallel to the direction of travel. The manually actuatable longitudinal adjuster 3 has on both vehicle seat sides one respective first seat track 5 which is connected to the vehicle structure of the motor vehicle, and one respective second seat track 8 which is displaceable relative to the associated first seat track 5 in the longitudinal direction of the seat x and which may be locked to said first seat track 5. In this case, the first seat track 5 and the second seat track 8 engage around one another with their substantially U-shaped profiles with longitudinal edges bent inwards and/or outwards by the interposition of balls 9. The balls 9 serve both for the mutual guidance and for the reduction of friction between the seat tracks 5 and 8. In the present exemplary embodiment, on each vehicle seat side in each of the four corners of the common track profile of the two metallic seat tracks 5 and 8, two respective sets of three balls 9 with specific spacings are arranged in succession in the longitudinal direction of the seat x, the metallic balls 9 being retained by a total of two ball cages 10 made of plastics material.
For locking the first seat track 5 and the second seat track 8, three detent plates 12 are provided on each vehicle seat side, said detent plates in each case being movably guided in the locking direction z in the second seat track 8, and being configured for cooperation with the first seat track 5. Each detent plate 12 has a planar base body 12a which extends in the longitudinal direction of the seat x and from which in each case on both longitudinal sides of the base body 12 exactly two teeth 12b protrude in a transverse direction y, i.e. a front tooth 12b in the longitudinal direction of the seat x and a rear tooth 12b in the longitudinal direction of the seat x. The guidance in the second seat track 8 takes place by means of a guide
pin 12c which protrudes in the locking direction z from the base body 12a of the detent plate 12 and engages with clearance through a guide opening 8a in the second seat track 8, in the present case in the upper side thereof. The guide opening 8a is preferably formed with a slightly greater cross section than the guide pin 12c, in order to provide the possibility of compensating for clearance. A tension spring 14 which, on the one hand, is suspended on the associated detent plate 12 and, on the other hand, on the second seat track 8, pretensions the detent plate 12 in the locking direction z against the second seat track 8. The longitudinal direction of the seat x, the transverse direction y and the locking direction z which are located perpendicular to one another form a right-handed system. Each tooth 12b is profiled in the present case in a rectangular manner both in the x-z plane and in the x-y plane, all teeth having the same dimensions. Thus each tooth 12b - viewed in the longitudinal direction of the seat x - has a front tooth flank 12d and a rear tooth flank 12d.
The three detent plates 12 are arranged in succession in the longitudinal direction of the seat x with their base body 12a within the substantially U-shaped profile of the second seat track 8, all teeth 12b of the three detent plates 12 protruding through slots 16 in the side walls of the second seat track 8. Recesses 17 are provided to the side of the slots 16 in the side walls of the second seat track 8. The material region of the side wall between a slot 16 and a recess 17 or an adjacent slot 16 is denoted as a web 18. By means of the recesses 17, the material between the slots 16, i.e. the webs 18, is specifically weakened, as disclosed in DE 100 50 959 B4, the relevant disclosure thereof being expressly included in the invention. The slots 16 and the recesses 17 are of rectangular configuration, so that in each slot 16 the two adjacent webs 18 (and in the first and last slot 16 in the
longitudinal direction of the seat, the side wall of the second seat track 8) form in each case an edge 16a extending in the locking direction z for defining the slots 16, i.e. a front edge 16a in the longitudinal direction of the seat x and a rear edge 16a in the longitudinal direction of the seat x.
The teeth 12b are provided for engaging in detents 20 of the first seat track 5, the detents 20 being separated by projections 21 of the first seat track 5. The projections 21 have two flanks 21a which define the detent 20 arranged therebetween in the longitudinal direction of the seat x, as a result of which a front flank 21a and a rear flank 21a are defined. By "projection" is intended to be understood the material part, and by "detent", the gap in the material. The detents 20 and projections 21 are arranged in at least one row extending in the longitudinal direction of the seat, generally in two opposing rows in the transverse direction y. In the present exemplary embodiment, the detents 20 are formed in the downwardly-bent regions of the longitudinal edges of the first seat track 5, i.e. the semi-open detents 20 open downwards, whilst the projections 21 protrude downwards in the manner of teeth. The projections 21 taper towards their free end (i.e. counter to the locking direction z). In the exemplary embodiment, the two flanks 21a of the projections 21 are inclined at an angle of 6°±2° to the locking direction z and thus merge with a radius in the bottom of the adjacent detent 20.
The dimensions i.e. widths and spacings of the teeth 12b, slots 16, recesses 17, webs 18, detents 20 and projections 21 are specifically selected in the longitudinal direction of the seat x. The slots 16 are wider than the teeth 12b (for example a quarter wider), the rear tooth flank 12d of the front tooth 12b of each detent plate 12 then coming to bear against the rear edge 16a of the associated slot 16 and the front tooth
flank 12d of the rear tooth 12b coming to bear against the front edge 16a of the associated slot 16. The detent plate 12 is thus guided through the tooth flanks 12d facing one another. The webs 18 are all of the same width (for example half as wide as the slots 16), but may alternatively be different by up to three tenths. The recesses 17 are slightly narrower than the slots 16 (for example a tenth narrower). The detents 20 are wider than the teeth 12b (for example approximately twice as wide) . The projections 21 are slightly wider than the teeth 12b (for example a fifth wider at the free end). The distribution of the detents 20, i.e. the spacing between two front flanks 21a (or two rear flanks 21b) is slightly smaller than the distribution of the teeth 12b, i.e. the spacing between the two front tooth flanks 12d (or the two rear tooth flanks 12d) of a detent plate 12 (for example one to two hundredths smaller, i.e. with conventional dimensions ca. 0.1 mm to 0.3 mm). In the present case, the distribution of the detents 20 is 15.0 mm, and the distribution of the teeth 12b is 15.2 mm.
The aforementioned dimensions are selected so that in each longitudinal seat position the locking takes place without clearance by means of two teeth 12b belonging to different detent plates 12 for each row of detents 20. In one of the two engaged detent plates 12, the front tooth 12b bears with its (rear) tooth flank 12d facing the rear tooth 12b of the same detent plate 12, against the (rear) edge 16a of the associated slot 16 and with the (front) tooth flank 12d remote therefrom against the (rear) flank 21a of the projection 21 in front of the relevant detent 20. In the other of the two engaged detent plates 12, the rear tooth 12b bears with its (front) tooth flank 12d facing the front tooth 12b of the same detent plate 12 against the (front) edge 16a of the associated slot 16 and with the (rear) tooth flank 12d remote therefrom against the (front) flank 21a of the projection 21 behind the relevant
detent 20. In each case the bearing may take place in a punctiform or linear manner or over the entire surface. As a result of this state of the locked longitudinal adjuster 3 which is present in the normal case, both zero clearance and a quasi-stepless longitudinal adjustment are provided. The third detent plate 12 is located with its two teeth 12b on two projections 21. The longitudinal adjustment is only quasi-stepless, as in each longitudinal seat position one respective detent plate 12 may always be engaged, the second seat track 8 however exhibiting settling behavior, i.e. slightly moving during engagement until the second detent plate 12 is engaged.
In the event of a crash taking place in (or counter to) the longitudinal direction of the seat, the webs 18 are plastically deformed so that the teeth 12b of the two engaged detent plates 12 which have not participated hitherto, as well as of the third detent plate 12, come to bear against flanks 21a and/or edges 16a, as a result of which the entire longitudinal adjuster 3 is kept locked.
For unlocking the longitudinal adjuster 3, on each second seat track 8 are provided in a manner known per se a pivotably mounted unlocking flap 31 and between the two second seat tracks 8 a transverse tube 33 which is pivotably mounted and extends in the transverse direction y, with one respective arm 35 protruding to the rear on each vehicle seat side and with a lever 37 protruding to the front between the two vehicle seat sides, which is accessible at the front end of the vehicle seat 1 in the longitudinal direction of the seat. By pivoting the lever 37 upwards, the transverse tube 33 is rotated and pivots the two arms 35 downwards. Each arm 35 acts on the associated unlocking flap, which in turn acts on the guide pins 12c of the three associated detent plates 12, so that said detent plates are moved counter to the locking direction z and
as a result leave the detents 20. The second seat tracks 8 may thus be displaced relative to one another.
-Claims
1 Vehicle seat
3 Longitudinal adjuster
5 First seat track
8 Second seat track
8a Guide opening
9 Ball
10 Ball cage
12 Detent plate
12a Base body
12b Tooth
12c Guide pin
12d Tooth flank
14 Tension spring
16 Slot
16a Edge
17 Recess
18 Web
20 Detent
21 Projection
21a Flank
31 Unlocking flap
33 Transverse tube
35 Arm
37 Lever
X Longitudinal direction of the seat
y Transverse direction
z Locking direction
We Claims
1. A longitudinal adjuster for a vehicle seat, in
particular motor vehicle seat, comprising
a) at least one first seat track (5) with detents (20) which are arranged in at least one row extending in the longitudinal direction of the seat (x) , each detent (20) comprising a front flank (21a) and a rear flank (21a) in the longitudinal direction of the seat (x),
b) at least one second seat track (8) which is displaceable relative to the first seat track (5) in the longitudinal direction of the seat (x) and may be locked thereto,
c) at least two detent plates (12) for locking the first seat track (5) to the second seat track (8), the detent plates (12) being movably mounted in the locking direction (z) in the second seat track (8) and comprising teeth (12b) for engaging in the detents (20) of the first seat track (5) , each tooth (12b) comprising a front and a rear tooth flank (12d) in the longitudinal direction of the seat (x),
characterized in that
d) each of the detent plates (12) comprises exactly two teeth (12b) for each associated row of detents (20), and
e) two teeth (12b) belonging to different detent plates (12) cooperate with the row of detents (20) associated with said teeth (12b) for locking the first seat track (5) to the second seat track (8) with no clearance.
2. The longitudinal adjuster as claimed in claim 1,
characterized in that in the longitudinal direction of
the seat (x) the distribution of the detents (20) is
smaller than the distribution of the teeth (12b) of
each detent plate (12).
3. The longitudinal adjuster as claimed in claim 2, characterized in that the distribution of the detents (20) is one to two hundredths smaller than the distribution of the teeth (12b).
4. The longitudinal adjuster as claimed in one of the preceding claims, characterized in that the second seat track (8) comprises slots (16) from which the teeth (12b) of the detent plate (12) protrude, the slots (16) in the longitudinal direction of the seat comprising a front edge (16a) and a rear edge (16a).
5. The longitudinal adjuster as claimed in claim 4, characterized in that, between the slots (16), webs (18) of the second seat track (8) are arranged as
material.
6. The longitudinal adjuster as claimed in claim 5, characterized in that the second seat track (8) comprises recesses (17) which are adjacent to the slots (16), one respective web (18) being provided between one respective slot (16) and one respective recess (17).
7. The longitudinal adjuster as claimed in claim 5 or 6, characterized in that the webs (18) have the same width or differ from one another by up to three tenths.
8. The longitudinal adjuster as claimed in one of claims 4 to 7, characterized in that in the normal case one of the two teeth (12b) of one of the two engaged detent plates (12) bears with its front tooth flank (12d) on the front edge (16a) of the associated slot (16) and with its rear tooth flank (12d) on the rear
flank (21a) of the cooperating detents (20).
9. The longitudinal adjuster as claimed in claim 8, characterized in that in the normal case one of the two teeth (12b) of the other of the two engaged detent plates (12) bears with its rear tooth flank (12d) on the rear edge (16a) of the associated slot (16) and with its front tooth flank (12d) on the front flank (21a) of the cooperating detents (20).
10. The longitudinal adjuster as claimed in claim 8 or 9, characterized in that in each case the other of the two teeth (12b) of the two engaged detent plates (12) is spaced apart from the flanks (21a) and edges (16a) and thus in the normal case does not participate in the cooperation.
11. The longitudinal adjuster as claimed in claim 10, characterized in that, in the event of a crash, the webs (18) are plastically deformed so that the teeth
(12b) of the two engaged detent plates (12) which have not participated hitherto, come to bear against flanks (21a) and/or edges (16a).
12. The longitudinal adjuster as claimed in one of the preceding claims, characterized in that on each vehicle seat side, one respective first seat track (5) and one respective second seat track (8) are provided, the two second seat tracks (8) bearing in each case three detent plates (12).
13. The longitudinal adjuster as claimed in claim 12, characterized in that, in the event of a crash, the third detent plate (12) engages in the first seat track (5) .
14. The vehicle seat comprising a longitudinal adjuster as claimed in one of the preceding claims for adjusting the longitudinal position of the seat.
